How to Sign PDF Documents on a Phone or Computer

The old routine was to print the document, sign it, scan it and email it back. That takes a printer, a scanner and patience. Placing a picture of your signature straight onto the PDF gets the same result in a couple of minutes. Before you rely on it, though, it helps to know what kind of signature this is.

Two different things are called a signature

The first is a picture of your handwritten signature placed on the page. It is the digital version of signing with a pen. It shows your agreement, and people accept it for many everyday purposes, such as rental forms, internal approvals, permission slips and quotations.

The second is a certificate based digital signature. It uses a cryptographic certificate issued to you. It proves who signed, and it shows whether the document was changed afterwards. Some banks, courts, tax authorities and government portals require this kind. The DocBrio tool creates the first kind. It cannot create the second. Which one is valid for your document depends on the law of your country and on what the receiver accepts, so when the document matters, ask them.

Worked example: signing a rental agreement on a phone

1. Read the whole agreement before anything else. A signature means that you have.
2. Open the Sign PDF tool on your phone and choose the PDF.
3. Draw your signature with a finger. Turn the phone sideways for more room, and try again until it looks like your normal signature.
4. Go to the page with the signature line and tap where the signature belongs. Drag it into place, and drag its corner until it is about as tall as the printed text around it.
5. If the form asks for a date or your printed name, add them as text next to the signature.
6. Save the signed PDF and open it once. Check that the signature is on the right page and does not cover any text.
7. Send the signed copy, and keep one for yourself.

Common mistakes

• A signature that is much too large. It looks careless and can hide part of the text. Match the size of a handwritten one.
• Signing only the last page when every page needs initials. Read the instructions on the document.
• Typing your name in an ordinary font and calling it a signature. Some receivers reject that. A drawn signature is closer to what they expect.
• Signing something you have not read, because it is quick on a phone.
• Sending a photo of the screen instead of the saved PDF.

Troubleshooting

• The signature looks shaky: draw it larger and more slowly, and then make it smaller on the page. Shrinking smooths small wobbles. A stylus helps as well.
• The PDF will not open: it may be password protected or locked against changes. Ask the sender for an unlocked copy.
• The receiver says it is not valid: they probably need a certificate based signature or a signature on paper. Ask which method they accept.

When this method is not enough

Do not rely on a drawn signature for documents that have to be notarised or witnessed, for property transfers, for court filings or wherever an authority names a specific signing system. In those cases the form of the signature is part of the legal requirement. If you are unsure, ask the receiver or a lawyer. This guide is general information and not legal advice.

Keep your signature safe

A picture of your signature can be copied by anyone who has a file containing it. Send signed documents only to the people who need them, and do not post them publicly. In the DocBrio tool your signature stays in the browser and is not saved by the site, so you draw it again next time.

Checklist

• I read the whole document.
• I know that a drawn signature is acceptable for this purpose.
• The signature is on the correct page, at a natural size, and covers no text.
• Date, name and initials are added where the form asks for them.
• I saved a copy of the signed PDF for my records.